In many different types of business forms handling equipment, there are situations where during handling of the forms the forms are not positively supported along their entire extent in the direction of feed. For long grain forms (that is forms in which the orientation of the grain is in the direction of motion and thus the tendency for rigidity of the form in the direction of motion is high), that is not a significant problem. However for short grain forms, in which the grain is perpendicular to the direction of motion, such forms have a tendency to sag or droop, particularly if the business forms are single sheets, when the forms are not fully supported in the direction of motion. In order to accommodate that droop, a large number of prior art pieces of equipment have been proposed. While such equipment is satisfactory in achieving support, and/or creasing of the forms or sheets, this equipment has typically been unsatisfactorily complex.
According to the present invention, an apparatus for preventing sheet drooping during sheet feeding in a first direction, even short grain paper forms, is provided which is the ultimate in simplicity. While the apparatus according to the present invention is very simple, it is effective, and very versatile, being adjustable in many different ways to provide the optimum positioning of the sheet supporting elements depending upon the speed of feed, length of the forms, and rigidity of the forms, which adjustment can be quickly and easily accomplished.
According to one aspect of the present invention, apparatus for preventing sheet drooping during sheet feeding in a first direction in a generally horizontal plane where a sheet is not entirely supported by a conveyor comprises the following elements: Means for feeding forms in the first direction in a generally horizontal plane. And, means mounted below the plane for engaging, and supporting the bottom of a sheet moving in the first direction when the sheet droops. The means mounted below the plane comprising: a stationary rod; at least one collar mounted to the rod; and a support pin extending radially outwardly from the collar substantially perpendicular to the rod, the support pin making an engagement angle of between about 55 and 90 degrees with respect to a second plane parallel to the generally horizontal plane and passing through the rod. The engagement angle optimally is about 60.degree.-85.degree., preferably 60.degree..
The apparatus also comprises first adjustment means for mounting the support pin to the collar and the rod to allow adjustment of the engagement angle, and second adjustment means for mounting the collar to the rod to allow adjustment of the position of the collar and support pin along the rod (axially). The first and second adjustment means may comprise the same mechanism, namely a threaded bore in the collar extending radially from the rod, and a threaded clamping screw extending into the bore and frictionally engaging the rod to hold the collar in both the circumferential and axial position on the rod to which it has been adjusted. The threaded clamping screw may extend 90.degree. with respect to the support pin, and the support pin may comprise a truncated cone end, with a rounded tip at the end for engaging a sheet.
The apparatus further comprises third adjustment means for adjusting the position of the rod with respect to the feeding means. The third adjustment means comprises first and second notched side plates extending parallel to the first direction on opposite sides of the rod, and engagement means for engaging the side plates and holding the rod in position in a pair of aligned notches in the side plates. The engagement means may comprise a pair of outer collars mounted to the rod, opposite a side plate from the support pin; and at least one roll pin mounted on each the outer collars for engaging a side plate and precluding rotation of the rod in the notch. The engagement means preferably further comprises at least one elastic band extending over the rod for biasing the rod into the notches, but allowing movement of the rod out of the notches against the biasing.
The feeding means may comprise a plurality of conveyor tapes spaced from each other in a direction perpendicular to the first direction, the tapes terminating in an end roller spaced from the rod in the first direction.
Weighted nip wheels on movable arms also can be provided, above a horizontal plane centering the forms, to exert a downward pressure.
According to another aspect of the present invention a support pin assembly is provided comprising the following elements: A disc shaped collar generally disposed in a plane and having a central through extending bore extending perpendicular to the plane. A first radial bore in the collar. A second, threaded, radial bore in the collar intersecting the central bore. A support pin disposed in the first bore and extending radially outwardly therefrom past the periphery of the collar. And, a screw threaded fastener disposed in the second bore and being movable in the second bore by screw threaded engagement with the second bore to intersect the central bore.
The first and second bores are typically at substantially 90.degree. with respect to each other, and the support pin typically has a truncated cone end with a rounded tip. The assembly also preferably comprises a rod extending through the central bore, the collar releasably held to the rod in a circumferential and longitudinal position to which it has been moved by frictional engagement between the screw threaded fastener and the rod. There also may be provided means for mounting the rod in different positions in a first dimension perpendicular to the rod, the mounting means comprising: First and second side plates each plate having a plurality of notches formed therein spaced from each other along the first dimension, pairs of notches in the side plates being aligned with each other; and engagement means for holding a rod in a pair of notches without allowing rotation of the rod in the notches, the engagement means including a pair of outer collars mounted on the rod remote from the support pin containing collar, each collar having at least one roll pin extending parallel to the rod and engaging the side plate, and at least one elastic band acting between the rod and at least one of the side plates for biasing the rod into the notches.
It is the primary object of the present invention to provide for the simple yet effective prevention of sheet drooping during sheet feeding, where the sheet is not entirely supported by a conveyor, especially in the feeding of short grain business forms. This and other objects of the invention will become clear from an inspection of the detailed description of the invention, and from the appended claims.